The Rockies play four games in San Francisco starting Monday, and with the Giants leading the National League West and playing games of consequence, Tracy doesn't want to start the inexperienced Pacheco in San Francisco.

Pacheco was drafted as a second baseman in 2007 and began the conversion to catcher in extended spring training in 2008. He caught exclusively until late August of last year at Triple-A Colorado Springs when he began playing third base in advance of being called up by the Rockies in September.

Last year, Pacheco started one game at catcher and played one inning in another. This season, he caught the entire game July 22 at San Diego. Pacheco has been playing third base (80 starts) and first base (22 starts) this season.

"I'm definitely excited to get back there again," Pacheco said of catching. "I missed it a little bit. Not too much but a little bit. I put a lot of time into it, blocked a lot of balls."

Pacheco said he will start catching bullpen sessions to help prepare for playing a game at that position.

Hamstring surgery to end Hernandez's season

DENVER -- Rockies catcher Ramon Hernandez underwent a second MRI on Wednesday that revealed a torn tendon in his left hamstring. He will undergo surgery next week and is done for the season.

Hernandez suffered the hamstring injury in the fourth inning Monday night. He pulled up running to first base after hitting a ground-rule double. This is the second significant injury this season for Hernandez, 36, who signed a two-year, $6.4 million contract with the Rockies as a free agent last winter. He missed 42 games before the All-Star break with soreness in his left hand.

Hernandez hit .217 in 52 games with five homers and 28 RBIs. He was signed to be the Rockies' regular catcher and to mentor rookie Wilin Rosario but lost his starting job while being sidelined with his hand injury.

Nuts' win gives De La Rosa another shot to start

DENVER -- Rockies left-hander Jorge De La Rosa is expected to make a third rehab start for high Class A Modesto after the Nuts advanced to the California League championship by beating Bakersfield, 6-2, on Wednesday in the decisive fifth game of their semifinal series.

Before the Rockies lost Wednesday to the Giants, manager Jim Tracy said De La Rosa's next start would hinge on whether any Rockies affiliates are still involved in the playoffs.

De La Rosa pitched 3 2/3 innings in his last start Monday for Modesto against Bakersfield and is scheduled to next pitch Saturday. Modesto will play Lancaster for the Cal League title. The third game of the series is scheduled for Saturday at Lancaster.

De La Rosa underwent Tommy John surgery in June 2011 and twice had rehab assignments halted this season. He began his current rehab assignment Sept. 5 and threw three scoreless innings for Rookie-level Grand Junction.

Low Class A Asheville is the other Rockies affiliate still in the playoffs. The Tourists are playing Greensboro for the South Atlantic League championship. That best-of-five series is tied 1-1 and scheduled to conclude Saturday at Greensboro if it goes to a fifth game. The certainty of Modesto playing Saturday makes it highly likely De La Rosa will again pitch for the Nuts.

The Rockies and De La Rosa are hopeful he will be able to start for Colorado before the end of the regular season Oct. 3.

Rockies giving Rutledge a look at second base

DENVER -- Rockies shortstop Josh Rutledge made his second career start at second base Wednesday.

"I want to see a little bit more of that," manager Jim Tracy said.

Rutledge made his Major League debut there Sept. 6 at Atlanta. Jonathan Herrera started Wednesday at shortstop, making just his second start in six games. Tracy has said he will only start Rutledge at second with either Herrera or Troy Tulowitzki at shortstop.

The latter continues to do all baseball activities, but Tracy had no timetable as to his possible return. Tulowitzki last played for the Rockies on May 30 when he strained his left groin and underwent surgery June 21 to remove scar tissue from a nerve in the groin area.

Scahill pleased with first Major League outing

DENVER -- After watching five games, Rockies reliever Rob Scahill, 25, finally made his Major League debut Tuesday and pitched a scoreless inning against the Giants, allowing a two-out double to Buster Posey before getting Hunter Pence to pop out.

Scahill entered Tuesday's game in the ninth with the Rockies trailing, 9-6, and on their way to a 9-8 loss. He said the wait for his Major League debut "wasn't that agonizing" because he realized Tracy wanted to put him in a situation that would benefit Scahill.

"I was able to spot my fastball pretty good," said Scahill, who threw 13 of his 22 pitches for strikes. "My curveball was pretty good. I yanked a couple sliders and I just kind of put that on the shelf. I went a little deeper in counts than I would've liked, but that'll happen."

Jack Etkin is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.